"Foursquare, for instance, ended up delegating all gamification features to a separate app named Swarm that never really managed to stay as relevant as its parent."

"Stack Overflow explains its success as having nothing to do with the points and badges."

"The very notion of a “game”"

"(Ab)use of points, badges and leaderboards. This is the most visible and annoying aspect of gamification. Product designers started to attach virtual currencies to anything, under the silly premise that if you offer people something to collect, they will try to collect it no matter what."

"Displacement of rewards. It’s been demonstrated that offering any kind of reward on behaviors that should happen spontaneously puts people into “transaction mode”, altering the original motivations system and leaving them less motivated than before."

"Condescending tone. Many gamified systems, for the sake of keeping users motivated, adopt a patronizing treatment, congratulating people in an overly cheerful voice for everything they do."

"Duolingo: Adding fun to something that people already wanted to do"

"The key is that it provides a fun way of learning something that people already wanted to learn."

"Passing these levels is just the right amount of difficulty, so you will probably make a few mistakes, which in turn actually enhances the sense of unpredictability that is key to keeping you engaged."

"2. Sublime Text: making power users even more empowered"

"3. GitHub: a true leaderboard and a valuable currency"

"4. Trello: visualizing progress and accomplishment"

"You don’t need to be awarded with badges — the intrinsic reward of seeing a task done is enough."

"Make the users feel smarter."

"Enable discovery of advanced features."

"Create slick, elegant UI."

"Let users define their standards for progress."

"Show users how far they’ve progressed."

"Design for “flow”"

"Avoid the trap of virtual currencies."